Open Source in the Military?

djmcmath asks: "Does anyone have any experience with Open Source Software and/or GPL'd software in military applications? I'm only asking because I'm involved in work on the combat systems for a new submarine, and had considered an Open Source solution. (I apologize, I must be intentionally vague for obvious reasons.) So ignore the obvious questions (Is it really suitable? Are closed-source proprietary options better? Does MS have a good solution?) and skip to the good stuff. What about the fact that my code would be classified Secret under US Code Umptifratz? I cannot distribute my code (and it's changes) without being tried for treason. What happens to the rest of the combat system code when I submit my GPL'd module?" Open Source and the Military: it's a tricky combination of keeping what can be open, open and keeping your secrets...well, secrets! However, open source in the military need not be as high profile as weapons systems. One of the only major OS projects that I'm aware of that had any form of military involvement was GRASS, the open-source GIS system. I'm sure there may be a few others out there. Does anyone know of other OS projects with military association? If there are any projects out there that interface with classified bits, how did you deal with those issues?